Because of too many reasons
- Man Utd have not pulled any trees in last 5 years. The club is no longer a sought after destination in terms of success. Even in our best of years, we were still next to the likes of Barcelona and Real, who are consistently in CL last stages.
- Our manager is not a sought after manager. We have managers like Pep in the same city who unfortunately has a better reputation. It doesn't really matter if he is a better manager or not.
- Given the top 2 conditions, we would need to pay over the top for any extra talented player to swerve his mind. Again not all players are swerved by money and even though we are rich, we still have a transfer budget. And again, the more a player costs, the more criticism he gets (even from fans).
- Weather and city as always. Many players see Spain as a much preferred destination than rainy England. Some players genuinely perform better under brighter conditions. Also London is the better choice than Manchester. So even if they were coming to England, many would prefer London. It was not a problem when we were top dogs. A problem if we are not.
- German talents see Bayern as the ultimate aim and all Bayern needs to do is make a call. They all come for peanuts.
- Negative media reputation does not help. We are always under scrutiny. So small problems in team appear many times larger because we are constantly in the media. Again, it did not matter when we were top dogs and had one of the best managers in the world, but starts to matter when we don't have those.
All this does not mean, it will get fixed if we fire Jose. I doubt if there is someone on the market who is that much sought after.