I don't know how big your garden is, but my belief is, unless you've got a very large garden, everything in the garden should be a good "doer", i.e., it looks good most of the time. I'd have that out in a heartbeat (but then I'm pretty ruthless!) and think carefully about a replacement. Bear in mind that, unless you particularly want a certain fruit, fruit trees are not great "doers" in the sense I described - I'd replace it with something beautiful with at least 2 seasons of interest, maybe Amelanchier lamarckii. There are other Malus varieties that perform better though, giving both flowers and a good fruiting in the autumn - 'Golden Hornet' and 'John Downie', for instance, plus then there's the purple leaved ones with red fruits in autumn, such as Malus 'Profusion'. The one you have currently is not grown for its fruit, but for its overall shape, with long, arching branches - course, what they don't tell you is there's not much else about it, apart from 2 weeks of blossom, that you might find attractive...

lichen is a sign of clean air. why not grow a clematis or 2 through it, one that flowers high summer then a late flowering one. Or a rambling rose and a clematis. I do this with trees with limited appeal. Or even morning glories. You could change the colours every year. and if you love the blossom why throw it away. I love lilac but it is very boring for the rest of the year.

Sbg and I are thinking along the same lines. I planted a clematis ('Marie Boisselot') about three years ago to climb into my malus floribunda.
One thought - do you have apple trees in your garden? I have two and there has been a much better crop on them since I planted the malus

Well! There's food for thought! Bamboo you nearly got me running for the axe, and I still might, but am now wondering whether to give clematis a try--I have 2 new ones waiting to go in somewhere. The malus, however, stands in full sun and the bole doesn't throw very much shade so do you think clematis would survive? Maybe I just have to try it and see. Gardening does seem to be trial and error--mostly error on my part!
Thanks for the advice. I think I might enjoy the blossom for this spring and try the clematis. Then if it doesn't do, I can root it out and put in an amelanchier in the autumn.

Don't try and plant the clematis right against the tree as the soil will be full of tree roots and the leaf canopy will prevent any rain getting to it. Plant it a little away and 'lead' it to the tree with a cane. The north side of the tree would be best to shade the clematis roots

Thanks Andrew, I'll give it a go.