My belief is that toddlers and preschoolers are learning all the time. In our culture unfortunately we often define "learning" as about academic learning like reading and math. Much of the important work of these early years involves different kinds of learning - social skills, motor skills, sensory development, development of the imagination, ability to self regulate and cope with emotions, etc. What many people don't seem to realize is later academic success depends in large measure on these nonacademic skills. Ability to direct yourself and cope with frustration as vital to coping with challenging academic material. Upper body muscle helps with handwriting. Imagination is required to be a good writer, etc. etc. etc.
The development of many of the things you've mentioned can be influenced by parents. We had a thread a while ago on hothousing social skills. We know some parents are pushing their children into sports, which requires practicing motor skills. Is hothousing as a term meant to describe only academic progress? If you spend a lot of time with your child creating opportunities for them to learn social skills, practice motor skills, develop creativity, etc... then are you hothousing?
So, no, I don't at all regret that I didn't teach my child academics sooner. I was quite confident academics would come to him easily and they have. It is the other stuff that I knew would be harder and have more risk of derailing his life happiness.
Perhaps I'm reading this wrong, but you make it seem as though you never did anything academic with your child in early childhood. I don't see why everything shouldn't be taught in moderation, including academics. Would a couple of minutes a day playing Starfall be so detrimental to development in other areas that it should be avoided?
Part of why I started this thread is to consider other people's opinions on parenting and child development, as I'm certainly no expert, and I definitely want to be a good father. What I read here could very likely change the way I father my children.
Having said that, maybe I'm a hothouser, but maybe not in the traditional sense. I definitely make my children the focus of my life. I almost always put off doing chores until they go to sleep, specifically so that I can spend that time doing things that I think benefit them developmentally. We spend our time doing a wide variety of activities, as I also understand that there is much more to development than academics.
However, I have flashcards, and I've used them. I have a few leapfrog products too. I know how my daughter learned her letters... she learned them from Fridge Phonics in minutes a day, usually while I was making her breakfast. She thought it was fun and wanted to "earn" every letter we had (I only put up a few to begin with, so as not to be overwhelming. She earned a new letter by showing she knew the ones already on the fridge.)
On those same days we probably practiced going up and down the stairs a dozen times or more. I'm not sure why she wanted to do that, but it seemed developmentally appropriate to me, and safe enough under careful adult supervision. We probably played with play-doh, which I consider to be not just an artistic outlet, but a 3-d modeling tool. I'm sure we pretended to cook a dozen different dishes too, often grabbing imaginary ingredients out of thin air. We walked around the block, and discussed everything we saw. We sang countless songs and read countless books, including her long-time favorite: a picture book dictionary. (A very annoying book for a parent to read repeatedly, IMO) On trips to the park, I encourage my introverted daughter to initiate playing with other children, and sometimes she does. When she doesn't, I let her know that's OK too.
Other parents have mentioned her extensive vocabulary, and I wonder if they would consider all that time reading the dictionary to be hothousing. I know that I read her fewer books than she would have liked, and often steered her away from that particular one (for my own sanity). Still, maybe I am a hothouser. I try to make every second of her day as enriching as I can, but in many different areas, of which academics is only a small part. She's the one who forced herself into the writing class at daycare at the age of 26 months, but I didn't veto that decision. I even help her practice. I can't imagine she came up with the proper writing grip on her own. I suspect she had to be taught, and I'm ok with that.