Mikko - I think you are right in the way the the whole scene is getting more professional. Material is getting better, but also the "modern" players are better. Yes, our heroes of the past were maybe more charismatic, but today, a cleaner way of pool is played.
Examples:
When I go and play pool at a pool hall, the material is maybe well maintained and clean - but if you play on a table with new cloth and you use balls of tournament grade - that's way of a difference! A soft draw shot of 3 feet (between cue ball and object ball) on my home table just stops, same in the pool hall - but on tournament level, the CB travels way back, reacting much more sensitive.
If you watch a game between Josh Filler, Fedor Gorst, Johan Chua or some other Philippinos - if they make 2 or 3 mistakes, the match is lost. In the past, they were maybe a bit more creative, but nowadays, the level of cueball control is really higher.
As to what custom cues is concerned - it is a bit like cooking, I think.
If you are a hobby chef and you love to cook on weekends for friends and family - if you can afford it, you will buy an expensive damascus knife. Working with nice tools makes just more fun. Unfortunately, the taste of the dish is not proportional to the price of my knives. But if you are a professional chef or a butcher, then your knife will get consumed over time, due to the regular sharpening. So good stainless knifes that last 6 month (at most) for 30 or 40$ will be used.
Same with pool players: Amateurs might play with expensive custom cues, but the pros use a relatively cheap butt, a CF shaft and a tip to their liking. If the butt is 500$ or 5,000$ - that has basically no impact.
Bottom line: It will be difficult in the future to make a living as a cue builder.