Carbonfiberboy 

One certainly does have to keep their form together. I call form deterioration "failure". A good reason for that is that one can move more weight with good form than with bad. There are many subsidiary muscles involved in holding good form, and we certainly don't want any of those to stop contributing - and if they do, well then that's failure. They failed.

I see so many cheaters and already-failed people working out at the gym - mostly men. It's like the amount of weight has some meaning. It doesn't. Only form has meaning. For the most part, women get that. Maybe they're just more stylish. As Style Man used to say, "Style is pain."

Beyond that, reaching failure is kinda the point, meaning that only at failure have all your muscle fibers been able to contract together to do the work, so it's a point of neuromuscular failure. That's the reason that one's max goes up so quickly when one starts a new program. Our bodies solve the problem of getting our nerves to find our muscles fairly quickly, maybe in as little as 6 weeks. Then boom, our advance slows greatly. The only way to get stronger then is to gain size or gain endurance. Most of us don't really want to gain size, so we don't increase calories. But very slowly, the amount we can lift with our skinny bods keeps going up. I don't know why though. Maybe we stay the same size because we're losing internal muscle fat and becoming more cut.

It used to be that at that neuromuscular sweet spot, many riders would start to do high rep sets to increase endurance. They'd still rep to failure to maintain that neuromuscular conditioning. That's fallen out of favor now because it robs too much energy which could be better spent on the bike doing the same thing. Climbing OOS until you can't anymore is a lot more fun and more useful. So now they drop the strength reps to 4 instead of increasing them and put in the extra time on the bike.