A lot of HVAC companies have gone corporate now. Smaller companies are bought out and consolidated, higher paid and experienced personnel are let go, cheaper replacements are brought in that don't have much of a clue how to deal with older established systems, but they will definitely tell you if something is broke after you told them it was broke and offer to sell you a brand new system install that they don't have to troubleshoot with the skills and experience they lack and has a much higher margin than replacing a simple rollout switch or swap a new transformer or control board.