The Guardian article does say that Sadiq Khan is not opposed in principle to the garden bridge but is concerned about the procurement process. That is, of course, an issue - the person appointed has only done one bridge but in the procurement process was apparently recorded as having "relevant design experience".
However, there are several other reasons why there is a great deal of opposition to this bridge being built at all.
There are many green spaces and large parks in central London (it is said to be the greenest city in Europe and the fifth greenest in the world) so there is no need for a garden bridge which will be very expensive to maintain - an estimated £3.5 million per year (and we all know that estimates rarely go down). Gardening experts have also questioned how the tree and plants are to be irrigated.
It is also to be sited in a space between two other bridges which are less than a 10 minute walk apart, and the proposed planting of trees is likely to obscure what is a wonderful unobstructed view towards St Paul's.
There are more than 30 prohibitions as to its use:
No running, no cycling, no music, no picnics, no groups of 8 or more, no visits after midnight, etc. etc. Names and addresses can be demanded of anyone who infringes any of these rules. It has been said that there will be queues to gain access and murmurs of a ticketing system being put in place.
For a bridge that is not really needed, it is an awful lot of money to spend when we are in the grips of an austerity regime, which has resulted in many public amenities in much less affluent areas of London and other parts of the country being closed. The total estimated budget is £175 million, with £30 million being provided by Transport for London and £30 million by the Treasury.