Playing a crap guitar may be a necessity - I didn't have £1000 for a plank with strings when I started playing at 8 years old, I had a cheap (£40 / $75) classical guitar made of plywood my parents bought me. It may even be a right of passage thing.

Acoustics will build finger strength, but there's no need to deliberately buy a bad one. Get a 'gripmaster' if you want to build strength. I think newer players (as a sweeping generalisation) are focussing too much on speed. Speed is in my opinion, a by product of a developed technique. Drilling yourself in to going faster is a fast road to tendonitis, and combining that with sky-high action and excessive string tension is a recipe for disaster in my opinion.

I have developed far more as a player since I started investing in pro-quality tools for the job. I still play a squire strat sometimes, but it's set up professionally.

If you knowingly buy a crap guitar, there must be something wrong with you...