No, they are not. I don't see why you are asking me this. Are you trying to tell me Portugal and Greece have more > 20º days than Spain? Perhaps, but you won't see as many people going up climbs in Greece or Portugal as you will see in Spain. By this I do not want to insinuate they are "superior" to anyone, let me be very clear, they are not. I think it's a combination of many things, like I said, weather, climbs, competitive level and desire.
You can climb the Angliru 9 months out of the year. You can climb beyond 3,000 meter mark in southern Spain 10 months out of the year if you want to. You can't say the same thing about northern Europe, where, for example, the Alpe D'huez is "virtually" closed 4-5 months out the year (November to March). Forget about the Alps (even on the Italian side) and England, where winters are harsh.
It's one thing when you wake up in the morning and it's 17º out and sunny... compare it to England's 8º and rain... you kinda get the point.
That is the reason most teams do their preseasons in warmer climates (Spain, southern Italy, Greece, Portugal, et cetera). Well, that and "Da Sauce", but that is a entirely different subject.