Why would the EU powers be trying to force the EU to accept refugees? That sounds pretty self-detrimental.

2 words: CHEAP WORKFORCE

But they say stuff like: "Diversity is our strength"

If they wanted to accept migrants/refugees they would just accept migrants/refugees. There's no benefit in forcing themselves to accept them when they clearly have the choice to do so anyway. Especially not to the point where they are struggling to deal with the scale of the influx of people.

The European Union is not a country with a single government making decisions. It has many separate countries with different opinions.
France, Germany and other liberal countries (Netherlands, Belgium, Sweden) want to accept ANY amount of migrants. Their opinion is that cheap workforce is good for the economy.
Middle and eastern european countries (Hungary, Poland, Czhechs, Slovakia, Austria) want border defense. Their opinion is that migrants are bad for culture and national identity.
You can check it out in the news: Merkel said from Germany: "Welcome refugees!" and Hungary built a border fence in the same time. And both of them are part of the European Union. Currently the EU is trying to make a law for accepting migrants so that every country does so. But not everyone agrees.

The liberals had this important argument in the debate so far: "We can't let refugees die." Even though most of the people coming to Europe were economic migrants. If the Syrian conflict is over they can't call them refugees anymore and lose this argument in the debate.

Refugees have to wait 3 months after being accepted by the German government before they can work, even then they require paperwork and work permits; it takes 4 years for them to be able to apply for and work in the same way as a German citizen. The estimated net loss that the German government suffered in 2015 was 0.3% of the GDP (the German government incurred costs amounting to 0.7% of the GDP and generated 0.4% of the GDP). So to say that the refugee crisis is good for the economies of liberal countries is misinformed at best.

I'm fully aware that different countries accept different numbers of refugees but liberal countries like Germany do not improve their economy by accepting refugees. The reason for the differences in intake of refugees is because of both the liberal nature of the countries ("we must protect all people") and the difference in economic power; countries like Austria simply don't have the same amounts of money as Germany and as a result don't have the resources to let in so many refugees.

Although European countries do accept larger numbers of economic migrants than refugees, that is entirely irrelevant to the Syrian conflict. These people are refugees not economic migrants as they are fleeing their home country due to it being unsafe; they may pick Germany or the UK over countries like France for economic reasons but this does not change their status as refugees.

Finally

The Syrian conflict is very much not over. And to say that countries like the UK are conducting air strikes in Syria in order to force refugees to come to the EU including the country that is conducting the air strikes, is nothing more than a conspiracy theory.